Hitherto, optical disks such as CD (Compact Disk) or DVD (Digital Versatile Disk) have been used as recording media for information signals, and various disk drive apparatuses using these optical disks as recording media have been used.
As a disk drive apparatus using optical disk as recording medium of this kind, there is known a disk drive apparatus comprising a disk drive unit 200 constituted as shown in FIG. 1.
The disk drive unit 200 shown in FIG. 1 comprises a disk rotation drive mechanism 201 for rotationally driving an optical disk, an optical pick-up 202 for performing write or read operation of signals with respect to the optical disk rotationally driven by the disk rotation drive mechanism 201, a pick-up feed mechanism 203 for performing feed operation of the optical pick-up 202 in the radial direction of the optical disc, a FPC 204 having one end portion connected to the optical pick-up 202 and the other end provided in a manner extended in feed direction of the pick-up 202, and a circuit wiring board 206 on which a connector 205 to which the other end portion of the FPC 204 is connected is provided. These respective mechanisms and components are attached to a base 207.
The disk rotation drive mechanism 201 includes a flat spindle motor 209 at which a turn table 208 for holding the optical disk is provided, wherein the spindle motor 209 is supported by the circuit wiring board 206, and rotationally drives the optical disk in one body with the turn table 208.
The optical pick-up 202 converges light beams which have been emitted from semiconductor laser by an object lens 210 to irradiate the light beams thus converged onto the signal recording surface of the optical disk to detect, by light receiving element, return light beams which have been reflected on the signal recording surface of the optical disk to thereby perform write or read operation of signals with respect to the optical disk.
The pick-up feed mechanism 203 includes a pair of guide shafts 211a, 211b for movably supporting the optical pick-up 202 in the radial direction of the optical disk, a rack member 212 attached to the optical pick-up 202, a lead screw 213 meshed with the rack member 212, and a stepping motor 214 for rotationally driving the lead screw 213, wherein the stepping motor 214 performs movement operation of the rack member 212 which has been meshed with the lead screw 213 in the radial direction of the optical disk along with the optical pick-up 202 while rotationally driving the lead screw 213.
The FPC 204 includes a folded portion 204a folded back toward the bottom surface portion side of the optical pick-up 202, and a bending displacement portion 204b for allowing folded position of the folded portion 204a to undergo displacement in a manner following feed operation of the optical pick-up 202, and is drawn around between the optical pick-up 202 and the circuit wiring board 206.
The circuit wiring board 206 is the so-called rigid board, and is adapted so that a connector 205 to which the other end portion of the above-described FPC 204 is connected, a connector 215 for performing electric connection to other circuit wiring board or boards provided at the drive body side, and drive control circuits for performing drive control operations of respective units (components), etc. are mounted thereon.
The base 207 is comprised of sheet metal punched so as to have a predetermined shape, wherein an opening portion 216a for table to which the turn table 208 is faced and an opening portion 216b for pick-up to which the optical pick-up 202 is faced are continuously formed on the principal surface thereof. At the principal surface of the side opposite to the principal surface of the side where the turn table 208 and the optical pick-up 202 are faced from these opening portions 215a, 215b, there are attached the circuit wiring board 206, both end portions of a pair of guide shafts 211a, 211b, the lead screw 213 and the stepping motor 214 which have been described above, etc.
At the disc drive unit 200 constituted as described above, the disk rotation drive mechanism 201 rotationally drives the optical disk, and while the pick-up feed mechanism 203 is performing feed operation of the optical pick-up 202 in the radial direction of the optical disc, the optical pick-up 202 performs write or read operation of signals with respect to the optical disk.
Meanwhile, the above-described disk drive unit 200 is mounted at a disk drive apparatus 300 of the very thin type shown in FIG. 2. The disk drive unit 200 is attached integrally with a disk tray 302 which is taken out from a casing or housing 301 of the disk drive apparatus 300 and is inserted thereinto in a horizontal direction.
Since such disc drive apparatus 300 of the very thin type is mounted at thin type information processing equipment, e.g., note-type personal computer, etc., the disc drive apparatus 300 undergoes various restrictions in thickness direction. In concrete terms, at the disk drive apparatus 300, spacing between the bottom surface portion of the optical pick-up 202 mounted at the disk drive unit 200 and the casing 301 becomes very narrow.
At the optical pick-up 202, as described above, there are mounted semiconductor laser, light receiving element, various optical parts (components) for guiding light beams which have been emitted from the semiconductor laser onto optical disk, and for guiding return light beams which have been reflected on the optical disk into the light receiving element, and/or biaxial actuator for performing displacement drive of the object lens 210 in a focusing direction and in a tracking direction, etc.
However, at the optical pick-up 202, while it is necessary to suppress the thickness of the entirety as minimum as possible, it is difficult to thin each thickness of parts (components) mounted thereat depending upon the kind thereof. Particularly, in the case where the disk drive apparatus 300 is caused to be of thin structute to such a degree that its thickness becomes equal to about 9.5 mm which is thickness equal to that of the Hard Disk Drive (HDD) unit, since there hardly exists portion for reducing size in thickness direction, e.g., liquid crystal device for correcting aberration mounted at the optical pick-up 202 is disposed in a manner projected from the bottom surface portion of the optical pick-up 202.
In this case, as shown in FIG. 2, a projected portion 202a of the liquid crystal device, which is projected from the bottom surface portion of the optical pick-up 202, comes into contact with the folded portion 204a of the FPC 204 folded back toward the bottom surface portion side of the optical pick-up 202.
For this reason, at the disk drive apparatus 300, when feed operation of the optical pickup 202 is performed in the radial direction of the optical disk D, the projected portion 202a comes into slidably contact with the FPC 204 to damage wirings formed at the FPC 204, or to give bad influence or effect on signals delivered to such wirings.
Moreover, at the disk drive apparatus 300, when spacing between the bottom surface portion of the optical pick-up 202 mounted at the disk drive unit 200 and the casing 301 becomes narrow, draw-around space of the FPC 204 which is draw around between the optical pick-up 202 and the circuit wiring board 206 also becomes narrow. In this case, at the bending displacement portion 204b corresponding to folded position of the FPC 204, since the radius of curvature becomes small, its elastic (spring) force is also increased.
For this reason, at the disk drive apparatus 300, there was the problem that load by elastic force of the FPC 204 is applied to the optical pick-up 202 so that bad influence is given on feed operation of the optical pick-up 202.
Particularly, at recent disk drive apparatus 300, there is mounted optical pick-up 202 capable of performing recording/reproduction of information signals with compatibility with respect to recording formats of different disks such as CD and DVD. In order to comply with such situation, also at the FPC 204, signal lines for performing drive control of the optical pick-up 202 with different recording formats are wired. For this reason, at the disk drive apparatus 300, the number of wirings of the FPC 204 is increased and the FPC 204 is thus broaden so that load applied from the above-described bent FPC 204 to the optical pickup 202 is also increased.
For reference, as an optical pick-up apparatus in which the entirety of the apparatus is caused to be of thin structure, there is an optical pick-up apparatus disclosed in the Japanese Patent Application Laid Open No. 2001-325740 publication. In the optical pick-up apparatus described in this publication, composite (compound) chip of semiconductor laser and light receiving element is directly plane-mounted with respect to wiring board frame comprised of metallic wiring board to thereby realize the thin structure of the entirety of the apparatus.
In addition, as a disk drive apparatus in which the influence with respect to vibration-proof leg by spring action of FPC has been suppressed, there is a disk drive apparatus disclosed in the Japanese Patent Application Laid Open No. 2001-229659 publication. In the disk drive apparatus disclosed in this publication, the FPC which connects between the unit mechanism supported by the vibration-proof leg and the control board is divided into two parts to dispose the portion at the connecting position to the unit mechanism in a manner substantially symmetrical with respect to the center of gravity of the unit mechanism to thereby suppress influence with respect to the vibration-proof leg by spring action of FPC.